The present invention relates in general to an apparatus and method for bonding a material to a molded, cast, forged or machined part which has a tapered or angled portion or surface to dimensionally correct, define, re-define or otherwise alter the dimensions of the part and particularly the tapered or angled portion or surface.
A number of assemblies and machines use molded, cast, forged or machined parts with apertures wherein the aperture passes at least partially or totally through the part. For example, a part used in processing equipment may have an aperture adapted to receive a roller. Certain known molding, casting, forging or machining techniques require forming the part with the aperture having an angled or tapered wall. If this wall is not altered or straightened prior to use, the roller in the above example only engages the narrowest portion of the part. This can cause excessive wear on that portion of the part, the roller or some other part in the processing equipment.
To solve this problem, conventional manufacturing processes form the part with a smaller aperture then needed and then mill, drill or machine the part to correct the dimensions of the aperture to form a larger purchase area or engagement surface. In some applications, a friction reducing material is coated on the inside tapered surface of such parts to decrease friction between the surface and a roller or other device engaging such surface. However, such coatings do not change the angle of the surface of such aperture to increase the purchase area.
Other parts are manufactured with an angled or tapered outer surface. Accordingly, there is a need for an apparatus and method for dimensionally changing the angled or tapered surface of such parts.
The present invention solves the above problem by correcting or otherwise altering the dimensions of a part. More specifically, the present invention provides an apparatus and method for bonding a material to a molded, cast, forged, machined or otherwise formed part having an angled surface or portion such as a tapered aperture to dimensionally correct, define, re-define or otherwise alter the part""s dimensions and specifically the angled surface or portion of the part. For purposes of this application, the term xe2x80x9cpartxe2x80x9d includes any molded, cast, forged, machined or otherwise formed part or workpiece.
The apparatus of the present invention preferably includes: (i) a sprayer; (ii) a bonding material delivery system or supply; (iii) a part rotating support, turntable, moving mandrel or other spinning or part moving apparatus; (iv) a sprayer positioner or sprayer positioning controller; and (v) a processor that simultaneously operates the sprayer, the supply, the sprayer positioning controller and the rotating support in concert. The apparatus uses the sprayer, the supply, the sprayer positioning controller, and the rotating support, as controlled by the processor, to bond a suitable bonding material (alternatively referred to as xe2x80x9cmaterialxe2x80x9d) to the part to meet the specifications of the manufacturer or ultimate user of the part.
In one embodiment for a part having a tapered aperture, the sprayer is inserted into the center of the angled or tapered aperture, preferably equally spaced from the inner surface or wall. The support holds and spins the part during the bonding process so that the material is bonded to the entire surface of the wall of the aperture. The sprayer applies bonding material at a predetermined spray rate, but moves at a differentiating withdrawal rate (i.e., the withdrawal rate decreases or slows as the sprayer is withdrawn from the aperture). As a result, more material is bonded to the tapered wall as the sprayer is withdrawn. This results in a cylindrical aperture having a straight or substantially straight wall with a predefined circumference.
In another embodiment of the present invention for a part having a tapered aperture, the sprayer is aimed towards the surface of the angled wall of the tapered aperture while the support spins the part. The sprayer is aimed at the inner surface at a predetermined angle. The sprayer has a predetermined spray rate, a spray cone of predetermined dimensions and a predetermined movement rate. As the sprayer moves relative to the aperture, the sprayer applies the bonding material to the wall of the aperture. The spray rate and movement of the sprayer are consistent throughout the process. This results in a cylindrical aperture with a straight or substantially straight wall having a predefined circumference.
Both alternative embodiments may also be employed to alter the angle of an outer wall of a part. It should also be appreciated that multiple sprayers may be used in accordance with the present invention.
Accordingly, the present invention provides a method for changing an angled surface of a part which includes positioning a part and a sprayer in relatively close proximity, supplying a bonding material to the sprayer and applying differing amounts of the bonding material to the angled surface of the part. The method further preferably includes rotating the part or the sprayer and moving the part relative to the sprayer or moving the sprayer relative to the part.
A further embodiment of the method of the present invention includes applying a bonding material to an angled surface of a part to alter the angled surface by moving the part, determining the placement of the part using a sensor adapted to communicate with a processor, selecting at least one sprayer from a plurality of sprayers based at least partly on the placement of the part and applying differing amounts of the bonding material to the angled surface of the moving part.
A still further embodiment of the method of the present invention includes altering an angled surface defining an aperture in a part by inserting a sprayer into the aperture in spaced relationship to the angled surface, withdrawing the sprayer from the aperture at a predetermined withdrawal rate and applying differing amounts of a bonding material to the angled surface using the sprayer, thereby altering the angled surface. This method includes withdrawing the sprayer from the aperture at a variable rate and particularly withdrawing the sprayer at a decreasing rate.
A yet further embodiment of the method of the present invention includes altering an angled surface defining an aperture in a part by positioning a sprayer with respect to a plane defined relative to a surface of the part, rotating the part, moving the sprayer along the plane at a predetermined rate and applying differing amounts of a bonding material to the angled surface, thereby altering the angled surface.
It is therefore an advantage of the present invention to provide an apparatus for bonding a material to a part having an angled surface.
A further advantage of the present invention is to provide a method for bonding a material to a part having a tapered aperture to alter the dimensions of the aperture.
Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like numerals refer to like parts, elements, components, steps and processes.